Aerial videos from local television station KTRK showed flames erupting from the refinery and plumes of smoke.

The Texas City refinery can process 260,000 barrels of crude oil a day, according to Valero’s website.

Michael Larsson, who was working at a Marathon Oil plant nearby, said his plant was under a shelter-in-place order as of 5:30 p.m., nearly an hour after the explosion.

“The whole building shook,” Larsson said. “I could feel the building vibrate. This office building I’m in is made for these type of events, so I knew it must be something pretty serious when the building shakes.”